(CNN) — Human activity and climate change have left about 75% of the world’s coral reefs threatened, putting the livelihoods of many countries that depend on the ocean ecosystems at risk, according to a report released this week.
Local threats such as overfishing, coastal development, and watershed- and marine-based pollution are responsible for the immediate and direct threat to more than 60% of the world’s reefs. Add to that thermal stress from rising ocean temperatures and the number of threatened reefs jumps to 75%, the World Resources Institute found in the report, titled “Reefs at Risk,” released Wednesday.
“This report serves as a wake-up call for policy-makers, business leaders, ocean managers, and others about the urgent need for greater protection for coral reefs,” said Jane Lubchenco, administrator of the National Oceanic and Atmospheric Administration. “As the report makes clear, local and global threats, including climate change, are already having significant impacts on coral reefs, putting the future of these beautiful and valuable ecosystems at risk.”
The threat is the highest in Southeast Asia where nearly 95% of the region’s reefs are threatened, mainly due to overfishing and destructive fishing, according to the report. Australia, home to the world’s largest reef system, the Great Barrier Reef, had the lowest threat level at 14%.
The numbers represent an alarming trend: a dramatic increase in the percentage of reefs rated as threatened. According to the report, the level has increased by 30% in 10 years, mainly due to a rise in overfishing and destructive fishing.
The report attributes the rise to the growth in coastal populations in the Pacific and Indian Ocean regions.
Similarly, climate change is playing an increasing role in the growing threat levels as the warming atmosphere causes ocean temperatures to rise.
As a result, “mass coral bleaching, a stress response to warming waters, has occurred in every region and is becoming more frequent as higher temperatures recur,” the report says, noting that “extreme bleaching kills corals outright.”
“Our projections suggest that during the 2030s, roughly half of reefs globally will experience stress sufficient to induce severe bleaching in most years,” the study says. “During the 2050s, this percentage is expected to grow to more than 95%.”
Many countries, especially small island nations in the Pacific and Caribbean, rely on coral reefs for fishing, tourism and coastal protection, and the report says that “degradation and loss of reefs will result in significant social and economic impacts.”
In addition to the global threats of warming oceans and acidification, the local threats pose the most immediate and direct risks, the report finds, threatening more than 60 percent of coral reefs today.
This analysis addresses the local threats of:
- Coastal development, coastal engineering, land filling, runoff from construction, sewage discharge, and impacts from unsustainable tourism
- Watershed-based pollution such as erosion and nutrient fertilizer runoff from agriculture that flows down rivers to coastal waters
- Marine-based pollution and damage such as solid waste, nutrients, toxins from oil and gas installations and shipping, and physical damage from anchors and ship groundings
- Overfishing and destructive fishing, including unsustainable harvesting of fish or invertebrates, and damaging fishing practices such as the use of explosives or poisons.
The 27 countries and territories identified as highly vulnerable to reef loss are spread across the world’s reef regions. Nineteen are small island states.
Nine countries – Haiti, Grenada, the Philippines, Comoros, Vanuatu, Tanzania, Kiribati, Fiji, and Indonesia – are most vulnerable to the effects of coral reef degradation. The report points out that these countries have high ratings for exposure to reef threat and reef dependence, combined with low ratings for adaptive capacity.
In order to help with recovery, “local threats must be tackled head-on with direct management interventions, while efforts to quickly and significantly reduce greenhouse gas emissions are of paramount concern not only for reefs but for nature and humanity as a whole,” the report says.
Former Vice President Al Gore cautions in the report’s introduction that if efforts “fail to address the multiple threats they (reefs) face, we will likely see these precious ecosystems unravel, and with them the numerous benefits that people around the globe derive from these ecological wonders.”
- Three-quarters of the world’s reefs at risk (environmentaleducationuk.wordpress.com)
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Today I would like talk to you about Hawaii’s beautiful tropical …
In Hawaii we have about 600 different species of tropical reef fish and 25 % of those are endemic ( found nowhere else in the world but here ). Our fish in Hawaii are very special. Have you ever wondered how our fish got here or where did they come from? Let’s start by learning more about this.
Scientists believe that most tropical marine life ( even that of the remote Caribbean ) originated near Indonesia and the Philippines. More marine species are found there than anywhere else. In the Philippines, for example you can find up to 2,000 species of tropical reef fish.
How did they get here?
The ancestors of Hawaiian tropical reef fish drifted as larvae. But only species with long-lasting larval stages made it; those with short larval stages died before they got here. Ocean currents did not move them fast enough.
Once the fish got here they had to adapt to our water temperatures and evolve some time creating a different species, therefore becoming endemic or indigenous of Hawaii.
Here are photos & information on a few other endemic Hawaiian tropical reef fish.
Moorish Idol Hawaiian name: Kihikihi.
Common at any depths alone or in small groups. Scales are minute and not visible to the naked eye . Feeds upon sponge and encrusting invertebrates. Attains 9 inches. Hawaii, Indo-Pacific, Tropical Eastern Pacific.
Yellow Longnose Butterfly Fish, Hawaiian Names: La-u wi-li-wi-li nu-ku-nu-ku ‘o-i ‘o-i, and La-u ha-u.
Long Nose Butterflies are, as their names would imply, quite interesting in shape. Their elongated snouts distinguish them from many other Butterfly fish.
The Long Nose Butterfly is often found in pairs. These fish feed on small invertebrates, plankton, fish eggs, and various other items that they find scavenging in tiny cracks or crevices in reefs. The long-nosed adaptation that gives the Long Nose Butterfly its name aids it in this search for food.
Parrot Fish, Hawaiian Name: Uhu
Parrot fish inhabit shallow, tropical seas around the world. They are easily recognized by their parrot-like beak of fused teeth, a bluntly rounded head, large scales, and brilliant colors. Like their relatives, the wrasses, parrot fishes have a single continuous dorsal fin and swim with lazy rowing motions of their pectoral (side) fins.
Some Hawaiian endemic reef fish are unusual and not seen around our main Islands but abundant in the Northwestern Hawaiian Islands. For example, the Yellow Bar Parrotfish and the Lined Coris are uncommon to rare, while the Hawaiian Black Grouper and the Masked Angelfish (Blue Masked Angelfish in photo below) are almost never seen in our waters.
How to protect our reef fish.
Reef fish are a very important part of a healthy reef’s eco system.
All fish have a job to do. Some eat algae which keeps the reef’s clean from algae overgrowth, some eat parasites from other fish and marine life, which helps the fish stay healthy, indeed, the ocean works in a symbiotic way… everybody helps each other.
Remember these simple things:
When you go out surfing or snorkeling please remember do not step on the reef or touch anything.
Going in the ocean for surfing, snorkeling or free diving should be a completely visual experience. When I go in a protected area or a Marine Preserve I make sure my sunscreen is chemicals free or don’t use any sunscreen at all, instead I wear a long sleeve rash guard that protects me from the sun. These areas are visited by people by the hundreds on a daily basis and the chemicals in the sunscreen are harmful to the reef and the reef fish.
Never feed the fish or any marine animal. There is plenty for them to eat and what we eat is not meant to be eaten. Things like peas and corn and bread will only harm their digestive systems.
Pick up any rubbish you see and around beaches and the reef, little by little we can all help keep the reef’s clean.
Recycle so nothing ends up in the ocean.
Other Threats to reef fish in Hawaii
Did you know, one of the biggest threats to our tropical reef fish in Hawaii is the Aquarium Trade business i.e. Mainland Pet Stores?
“Forty five percent of all tropical reef fish sold in the USA mainland and pet shops come from Hawaii.”
For decades now our tropical reef fish have been taken from our islands and sold as pets all over the world. Some fish like the Hawaiian Cleaner Wrasse (blue and yellow fish in photo)only eat parasites, this fish will die within a month after taken from Hawaii.
The photo below is sadly of more than 600 dead fish discovered January 2010 in two bags in a Dumpster near a launch ramp at Honokohau small boat harbor on Hawaii. Mechanical pumps fail, big surf makes for difficult and dangerous catch returns, live wells on boats malfunction, and pipes leak, along with many other malfunctions, which cause this type of sad loss.
Many algae eaters like theare taken, therefore in some areas the algae has grown too much and it’s suffocating the reef and killing it. The Bandit Angelfish only eats sponges, they also die quickly and are quickly replaced by another… Imagine how many fish we have lost throughout the decades.
How can you make a difference? Education and information is the best we can do now. Inform all your class mates, teachers, friends and family about the troubles our Hawaiian tropical reef fish are going through, that helps a lot. Follow reef guidelines and remind others not to walk on the reef or take reef fish for aquariums. Ask questions and do research!
If you own a fish tank with Hawaiian tropical reef fish and you collected the fish yourself ( or your parents ) then you can return the fish to the same place they came from. If you bought the fish from a pet shop, please don’t buy any more and take good care of the fish you have now.
For more information on the Aquarium Fish Trade check For the fishes.org
Together we can protect our oceans and all marine life!
Thank you for doing your part,
Ocean Defenders and Ocean Girl Project Sustainable Surfers Hawaii
What You Can Do Links:
For more information on the Aquarium Fish Trade check For the fishes.org Snorkel responsibly, without damaging reefs.
Support efforts to cap carbon pollution at levels that won’t overheat the earth or turn our oceans more acidic.
- big fish gone missing from eastern caribbean reefs? (greenantilles.com)
- The Basic Life Cycle of Reef Fishes (brighthub.com)
- Just Listen to the Fish (sierraclub.typepad.com)
- Taking the pulse of coral reefs (eurekalert.org)
What do you do to help the reef? Feel free to leave suggestions, photos and comments!
Sharing an insightful, frightening and informative article from the guardian.uk
Yale Environment 360: Unless we change the way we live, the Earth’s coral reefs will be utterly destroyed within our children’s lifetimes, says marine scientist JEN Veron.
Tuesday 7 December 2010 10.03 GMT
One in four coral species are under threat of extinction. Photograph: Corbis
For me, an Australian marine scientist who has spent the past 40 years working on reefs the world over, these threats were of real concern, but their implications were limited in time or in space or both. Although crown-of-thorns starfish can certainly devastate reefs, the impacts of sediments, nutrients and habitat loss have usually been of greater concern, and I have been repeatedly shocked by the destruction I have witnessed. However, nothing comes close to the devastation waiting in the wings at the moment.
You may well feel that dire predictions about anything almost always turn out to be exaggerations. You may think there may be something in it to worry about, but it won’t be as bad as doomsayers like me are predicting. This view is understandable given that only a few decades ago I, myself, would have thought it ridiculous to imagine that reefs might have a limited lifespan on Earth as a consequence of human actions. It would have seemed preposterous that, for example, the Great Barrier Reef — the biggest structure ever made by life on Earth — could be mortally threatened by any present or foreseeable environmental change.
Yet here I am today, humbled to have spent the most productive scientific years of my life around the rich wonders of the underwater world, and utterly convinced that they will not be there for our children’s children to enjoy unless we drastically change our priorities and the way we live.
A decade ago, my increasing concern for the plight of reefs in the face of global temperature changes led me to start researching the effects of climate change on reefs, drawing on my experience in reef science, evolution, biodiversity, genetics, and conservation, as well as my profound interests in geology, palaeontology, and oceanography, not to mention the challenging task of understanding the climate science, geochemical processes, and ocean chemistry.
When I started researching my book, A Reef in Time: The Great Barrier Reef from Beginning to End (Harvard, 2008), I knew that climate change was likely to have serious consequences for coral reefs. But the big picture that gradually emerged from my integration of these disparate disciplines left me shocked to the core.
In a long period of deep personal anguish, I turned to specialists in many different fields of science to find anything that might suggest a fault in my own conclusions. But in this quest I was depressingly unsuccessful. The bottom line remains: Science argues that coral reefs can indeed be utterly trashed in the lifetime of today’s children. That certainty is what motivates me to spread this message as clearly, and accurately, as I can.
So what are the issues? Most readers will know that there have been several major episodes of mass bleaching on major reef areas worldwide over the past 20 years. In the late-1980s when the first mass bleaching occurred, there was a great deal of concern among reef scientists and conservation organizations, but the phenomenon had no clear explanation. Since then, the number and frequency of mass bleachings have increased and sparked widespread research efforts.
Corals have an intimate symbiotic relationship with single-celled algae, zooxanthellae, which live in their cells and provide the photosynthetic fuel for them to grow and reefs to form. The research showed that this relationship can be surprisingly fragile if corals are exposed to high light conditions at the same time as above-normal water temperatures, because the algae produce toxic levels of oxygen, and excessive levels of oxygen are toxic to most animal life. Under these conditions, corals must expel the zooxanthellae, bleach, and probably die or succumb to the toxin and definitely die. A tough choice, one they have not had to make at any time in their long genetic history.
We tend to think of temperature in terms of our day-to-day comfort level. We don’t have to be told that atmospheric temperature shows huge swings and variations from day to night, among seasons, and cyclically on other scales. Early critics of global warming used this variability to argue that there was no evidence for overall thermal increases. This missed the point and delayed our recognition of the true problem because atmospheric temperature is only a minor part of the Earth’s thermal picture.
By far the most important mobile heat sinks on the planet are the oceans. As the greenhouse effect from elevated CO2 has increased, the oceans have absorbed more heat. The surface layers are affected most as mixing to the depths can take hundreds of years. Large ocean masses such as the Indo-Pacific Warm Pool do not continue to warm further, but rather they broaden and deepen. Now they commonly become so large that their outer edges are pulsed onto the continental margins, where waters are warmed further. This creates the mortal dilemma for corals — to expel or not to expel their oxygen-producing zooxanthellae.
Ecosystems can recover from all sorts of abuse, and coral reefs are no exception. Good recoveries from bleaching have been observed, provided that further events do not occur while the ecosystem is re-establishing. Unfortunately, there are no signs that greenhouse gas increases are moderating, and so we can assume that the frequency and severity of bleaching events will continue to increase — on our present course, the worst bleaching year we have had to date will be an average year by 2030, and a good year by 2050. Ocean and atmospheric rises in temperature are also predicted to increase the severity of cyclones, which will add an extra burden on the recovery process.
Scientists don’t need a pocket calculator to conclude that compressing the time periods between events in this way will prevent recovery: If we do not take action, the only corals not affected by mass bleaching by 2050 will be those hiding in refuges away from strong sunlight.
But there is more bad news. A decade or so ago, we thought that mass bleaching was the most serious threat to coral reefs. How wrong we were. It is clear now that there is a much more serious crisis on the horizon — that of ocean acidification. This will not only affect coral reefs (although reefs will be hit particularly hard), but will impact all marine ecosystems. The potential consequences of ocean acidification are nothing less than catastrophic. The ultimate culprit is still CO2 but the mechanism is very different.
Normally there is a balance between CO2 in the atmosphere and its derivatives in surface waters of the ocean. As with temperature, the oceans act as a huge repository, absorbing and buffering any excess CO2 in the atmosphere. For this process to be efficient the oceans must have time for mixing to occur between its different layers, renewing the surface buffers from below. When CO2 increases too rapidly, these chemical reactions can falter, altering the balance of the buffers and gradually allowing the oceans to become less alkaline.
All organisms that produce calcium carbonate skeletons (including shells, crabs, sea urchins, corals, coralline algae, calcareous phytoplankton, and many others) depend on their ability to deposit calcium carbonate, and this process is largely controlled by the prevailing water chemistry. As alkalinity decreases, precipitation of calcium carbonate becomes more and more difficult until eventually it is inhibited altogether. The potential consequences of such acidification are nothing less than catastrophic.
In my book, I examine the events that led up to each of the five mass extinctions in Earth’s history. Corals offer a unique insight into the past, both because they have been around for most of the history of life on Earth and also because they readily fossilize. I examine the theories offered to explain these global extinctions and find that ocean acidification is the only explanation which fits the evidence well. Ocean acidification has played a major part in the marine devastations which took place in those ancient times.
A particularly galling aspect of the past four mass extinction events (very little is known about the first) is that, following them, reefs disappeared — not just for a few tens of thousands of years, but for millions of years — long after adverse climatic conditions may have returned to benign levels. One of the characteristics of acidification is that while it can be initiated by high CO2 levels over relatively short periods, there are no short-term geochemical fixes to reverse the process. Reversal can take place only through the immensely slow weathering and dissolution processes of geological time, processes that take hundreds of thousands to millions of years.
Ocean physics dictates that we will observe the effects of acidification in colder and deeper waters before it spreads to shallower tropical climes. The early stages of acidification have now been detected in the Southern Ocean and, surprisingly perhaps, in tropical corals. On our current trajectory of increasing atmospheric CO2, we can expect that by 2030 to 2050 the acidification process will be affecting all the oceans of the world to some degree. At that point, the relatively cool, deep-water tropical regions that have offered refuges to corals from temperature stress will be those most affected by acidification.
No doubt different species of coral, coralline algae, plankton, and mollusks will show different tolerances, and their capacity to calcify will decline at different rates. But as acidification progresses, they will all suffer from some form of coralline osteoporosis. The result will be that corals will no longer be able to build reefs or maintain them against the forces of erosion. What were once thriving coral gardens that supported the greatest biodiversity of the marine realm will become red-black bacterial slime, and they will stay that way.
Another concept of great importance is that of commitment — a word climatologists use only too often. Many of the consequences of our current actions cannot yet be seen, and yet the Earth is already committed to their path. This delayed reaction is due to the inertia of the oceans, both thermal and chemical. The greenhouse gases we produce today will take a number of decades (and sometimes more) to unleash their full fury, but their effects are unavoidable and unstoppable. We cannot afford to wait until the predictions of science can be totally verified, because by that time it will be too late. How many of us wish to explain to our children and children’s children that the predictions were there but we wanted confirmation?
Coral reefs speak unambiguously about climate change. They survived Ice Age sea-level changes of 120 meters or more with impunity. They once survived in a world where CO2 from volcanoes and methane was much higher than anything predicted today. But that was over 40 million years ago, and the increase took place over millions of years, not just a few decades, time enough for ocean equilibration to take place and marine life to adapt.
This is not what is happening today. Ponder these facts: The atmospheric levels of CO2 we are already committed to reach, no matter what mitigation is now implemented, have no equal over the entire longevity of the Great Barrier Reef, perhaps 25 million years. And most significantly, the rate of CO2 increase we are now experiencing has no precedent in all known geological history.
Reefs are the ocean’s canaries and we must hear their call. This call is not just for themselves, for the other great ecosystems of the ocean stand behind reefs like a row of dominoes. If coral reefs fail, the rest will follow in rapid succession, and the Sixth Mass Extinction will be upon us — and will be of our making.
- Coral reefs ‘could disappear in our lifetime’ (guardian.co.uk)
- Is the End in Sight for The World’s Coral Reefs? (e360.yale.edu)
- Dying Coral Reefs – 100 Million Lives are Already Threatened by Damages (brighthub.com)
- “Study: Coral In Caribbean Facing Worst Bleaching Event On Record” and related posts (aboutmyplanet.com)
- Bad News for Coral Reefs: Global Warming Causes Bleaching & Death (treehugger.com)
- Caribbean reef ecosystems may not survive repeated stress (physorg.com)